Are you sure the Green Martians haven't invaded your laptop ;-{
This looks like you pressed hard on the panel causing it to distort optically. Liquid Crystals are a type of polarizer material. If you take to Polaroid sunglasses turning them at right angles you'll see the light gets blocked and if you look at a strong light you'll see the small bit of light getting through is on the green side!
Sadly, you'll need a new display to fix this